Integrated circuits (“ICs”) are incorporated into many electronic devices. IC packaging allows for multiple ICs to be vertically stacked in “three-dimensional (3D)” packages in order to save horizontal area on printed circuit boards (“PCBs”). An alternative packaging technique, referred to as 2.5D packaging, may use an interposer, which may be formed from a semiconductor material such as silicon, for coupling one or more semiconductor die to a PCB. A plurality of IC or other semiconductor dies, which may be heterogeneous technologies, may be mounted on the interposer.
Many devices on one or more of the semiconductor die may cause electrical noise and/or create electromagnetic (“EM”) interference by emitting EM emissions. RF devices and inductors are examples of devices which can create electrical noise and EM interference. A noisy source, such as an RF device, generates electrical noise in signals carried in conductive structures such as metal leads. The electrical noise in the conductive leads can impact various other signals and devices in the package. Noisy electrical signals present serious problems in semiconductor packaging.